Karrie Jacobs, the former (and founding) editor of Dwell magazine, drove more than 14,000 miles looking for well-designed affordable housing, then wrote a book about it: The Perfect $100,000 House (Viking, $30). "Perfect" for her meant a house suited to a single person, compact yet with plentiful light, a bit of outdoor space and a modernist look. We asked her exactly what she discovered.

1. What started your quest?

After leaving Dwell, I'd cleaned out my apartment in San Francisco and left my cat in the care of a strange man. I was tired and miserable. Before driving back to New York for my real life, I was lent a tiny house in Bolinas on the California coast. It had a single big room with a south-facing glass wall and a pretty tolerable kitchen. There wasn't anything architecturally significant about the house. It was more like tub and a patio with all of Bolinas unfolding in front of it. The modesty and beauty of that house were in some ways triggers for my the guest cottage of a hippie chateau. But there was a nice, big, deep trip.

2. Like that cottage, your perfect house would also be tiny—around 1,000 square feet. The median home-construction cost is about $100 per square foot. So your ideal house should be buildable, right?

The smaller the house, the more it costs per square foot. In any case, that $100-per-square-foot figure is for production home builders doing subdivisions. Houses built by architects for single clients are, relatively speaking, a rare thing. Judicious use of materials, like off-the-shelf cabinets and windows, can bring down the price, as can a house in kit form.

3. You are a declared modernist. Yet you wrote that one inspiration for your perfect house is J. P. Morgan's magnificently ornate library in his New York mansion, now the Morgan Library. What gives?

What got to me was the systems of tiers and catwalks going all around the room that Morgan installed to access his books. It was a structure thing more than the opulence.

4. Did you find architects truly interested in designing a mere $100,000 house?

Some newly minted architects actually do come out of school wanting to build affordably. I think first of Chris Krager in Austin, Texas, whose focus is on the quality of space, not the quantity of space, which is where modernism leads. He did a pair of simple, lovely butterfly-roofed houses for around $95 per square foot, using low-cost materials like insulated concrete block for the walls and polished-concrete floors. But it's how Chris puts it all together that counts. He was especially brilliant in window placement. Being smart and sensitive about daylight is the best thing an architect can know how to do.

5. You visited a big L.A.-based mass-market builder, KB Homes, to find out if "they could build a house for someone like me." Could they? Would they?

I guess if they wanted to build me a modernist house, they could. But they won't, because they claim to build on the basis of marketing studies, which they do relentlessly. Would you pay more for a bigger bath? A Jacuzzi? Do you want a home office? But they don't see the point to asking if you prefer Mediterranean to Tudor because they assume the people they're asking don't know the difference.

The reason I was given for why they couldn't do modern was that it would involve flat roofs, which leak more than pitched roofs. "The clean look costs," they said. That's true. The connections between wall and floor and corner all have to be straight and true because there's no ornament or trim to hide where things don't quite line up. So it's hard to get the minimalist look right, which doesn't mean it can't be done. But you have to want to do it. So as long as mass home builders say there's no market for modern, why complicate their lives?

6. Prefab houses ought to be the answer to high costs. Yet the promise of prefab remains unfulfilled. What's the problem?

The prefab industry still exists mostly in the minds of architects. A very few have actually set up shop and are manufacturing house kits.But if you envision a prefab assembly line like in Detroit or a mega-factory in China, that's not happening. Most prefab enterprises that have sprung up try to reinvent the processes of stick-frame houses, which are already well established. They ship out walls, flooring and roofs, which the conventional-materials industry already does pretty well. The hard part is the innardsland clearing, plumbing, electrical system, the local-permitting process. So the prefabbers tend to replicate the most efficient part of the process but don't confront the big inefficiencies.

7. You've written that early modernism was "all about function, while today's modernism is chiefly about style." How did they diverge?
Modernism's origin as a social movement was to make functional architecture available to the masses by embracing the techniques of industry. But now it has become the style of choice for luxury custom homes built by architects. And that's kind of the joke—that modernism was supposed to eliminate craft and craftsmen for industrial processes, but now you have modernism as a style in which high-end craftsmen work very meticulously

8. You credit the late, inspirational architect Samuel Mockbee as "playing a big part" in your "obsession with low-cost housing." You visited Hale County, Alabama, where students at Mockbee's Rural Studio continue to design and build low-cost housing for "next to nothing."

The emphasis is on creative use of recycled materials. You admire the effort but also have reservations. Mockbee built memorable houses that put Rural Studio on the map. But if you're trying to eliminate substandard housing, is there a more
methodical way to do it? Each of those houses is an experiment made from unconventional materials. One is famously built from carpet scraps. How is that to be maintained over the years? It's not that poor people are incapable of keeping up such houses. I don't know how anyone would.

9. Of all the houses you investigated on your odyssey, which could become your very own perfect $100,000 house?

I loved an updated shot-trot house designed by Brett Zamore in Houston, Texas. It's a hybrid of two elemental Southern styles: the shotgun, which is a narrow, gabled house with all the rooms laid end to end, and the dogtrot, which has a covered central breezeway. Zamore's version is sleek, and it borrows from the past without nostalgia. His idea is to market his shot-trot as a kit, and it could be successful because it's just familiar enough and vernacular enough to get past people's biases about modern. And it could be built for $100,000. Then I'm thinking about a 21st-century version of an A-frame house. I want a small house that reads big, which the A-frame does. It's all bold structure—just two slabs that make the sides of a triangle, with the walls and roof one and the same.

10. Will you ever get your perfect $100,000 house?

I suppose that if I already had the land and the money in the bank, I'd have to make a final decision. But until then. . . .